"No one's told us to write it so that it ends," executive producer Pam Veasey

tells TVGuide.com with a laugh. "It is an incredible challenge each year to sort of leave it open. Once again, our objective was in [the characters'] personal lives. Have you learned something about each of our characters that says they will go on and they will grow and they are still the family that's wonderful and complete?"On the other hand, Mac (Gary Sinise), who was shot at the end of last season, is very much thinking about the future — particularly as it involves his girlfriend Christine (Megan Dodds). "In the first episode of Season 9, she's just devoted to Mac and his recovery. The deal is sealed almost at the beginning of this season," Sinise says of the relationship. "We established in the very beginning of the series that Mac is a grieving 9/11 widower. We established him as somebody who was troubled. For him to find love again at the end of our season — or series — is kind of special and very sweet."But Mac must first survive another dangerous situation. The finale (Friday at 9/8c, CBS) finds Mac and Detective Flack (Eddie Cahill) trapped in a police station with two officers who may or may not have shot and killed an unarmed man. When the community learns of the shooting, a large group begins rioting outside the police station and the scene quickly becomes sticky.

"This episode is based very loosely on a real event back in the '70s," Sinise says. "A police station was actually overrun by a group of people who were angry. They stormed the police department and something like 60 police officers were injured and people were hauled away. It was a big riot and a pretty big mess. Mac and Detective Flack are kind of barricaded inside the police and the rest of the team has to go out and find the evidence to figure out what actually did happen. It's pretty tense."Although he might not be in the same type of immediate danger he was in a year ago, Mac is forced to reflect on all he's been through this season. "It makes Mac's character think about mortality," Sinise says. "He's been dealing with those kinds of questions for the past season. It's a very emotional episode."And as Mac looks forward to a future with Christine, can viewers expect a proposal or some sort of serious gesture? Sinise hopefully (and coyly) suggests that might be a story best served in Season 10. "Mac's gone through a lot and has come to terms with a lot of things," Sinise says. "If we do come back for a Season 10, there will be some very hopeful things to do with the characters. ... It's a very nice ending. I think people who have watched these characters grow will enjoy it."CSI: NY'sseason finale airs Friday at 9/8c on CBS. Watch a sneak peek of the episode below.